Work out what a balcony solar kit would actually save you: your state's electricity rate, your kit size, your orientation, and the self-consumption rate that decides everything.
Use your bill: total dollars ÷ total kWh, including delivery charges.
This matters more than panel wattage. Exported surplus earns nothing.
Generation peaks at midday; most households peak in the evening. The shaded
overlap is the only part you are paid for — which is why "who is home during the day"
changes the return more than panel wattage does.
How this calculates
Annual generation is your kit's wattage times a per-state yield figure (roughly 950 to 1,600 kWh
per installed kW per year, from NREL's solar resource bands), derated 20% because a real balcony
rarely gets an ideal tilt, then multiplied by your orientation factor.
The saving is not generation times your rate. It is generation × self-consumption
× your rate, because in nearly every state that has legalised plug-in solar these systems are
excluded from net metering, so exported surplus earns you nothing. That is why the
"who is home" question moves the answer more than the kit size does.
Treat this as an estimate
Real output varies with shading, dirt, weather and how your utility bills you. On a
time-of-use tariff where peak is 4–9pm, midday solar offsets your cheapest hours, which
quietly reduces the value of every kWh. Use this to decide whether the idea is worth pursuing,
not as a forecast.
Editorial note: One Plug Solar publishes independent guides. Nothing here is electrical, legal, or financial advice. Plug-in solar rules differ by state, utility, and building, and they are changing quickly — verify your own situation before you buy or plug anything in.